During 2012, Los Alamos National Laboratory made its scientific mark in a variety of areas, and the stories that caught the public’s attention and that of the science community reflect the lab’s broad capabilities.

Top science stories for the year traveled from the canyons of Mars to the high desert forests of New Mexico, from cosmic particles to the structure of proteins and enzymes. Computer models of wildfires and nuclear magnetic resonance signatures of plutonium, and it was fascinating for those following Los Alamos’ science news.

Mars Science Laboratory Curiosity rover and ChemCam

Los Alamos played a role in the success of the Mars Science Laboratory mission and its six-wheeled wonder, the Curiosity rover. The international team of space explorers involved with the mission is relying in part on an instrument originally developed at Los Alamos called ChemCam, which fires an extremely powerful laser pulse to briefly focus the energy of a million light bulbs onto a pinhead-sized area on targets up to 23-feet away from the rover. ChemCam reads the resultant flash of light to determine the composition of the target, and is part of a suite of 10 instruments aboard the SUV-sized mobile laboratory that is determining the Red Planet habitability.

Los Alamos also has roles in other aspects of the Mars Science Laboratory. The lab developed aspects of another instrument called CheMin, which uses X-ray diffraction to determine the composition of mineral samples collected and dropped into a funnel on the Curiosity rover.

20 years of stockpile stewardship without nuclear testing

The Stockpile Stewardship Program carried out by scientists and weapons experts at Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Sandia National Laboratories and the Nevada National Security Site (formerly the Nevada Test Site) has significantly advanced the nation’s ability to understand the stockpile without nuclear explosive testing through analysis of legacy data and new data from sub-critical experiments, supercomputer modeling and simulation and other non-nuclear experiments.

“Because of the talent, intellect, creativity and determination of the scientists, engineers and technicians at Los Alamos, and across the NNSA’s nuclear enterprise, we have been able to deliver on the promise of Stockpile Stewardship for 20 years without full-scale testing,” Laboratory Director Charlie McMillan said. “It is our most important job, one that will continue well into the future.”

Studying climate imapcts on forests

Combine the tree-ring growth record with historic information, climate records and computer-model projections of future climate trends and you get a grim picture for the future of trees in the southwestern United States. That’s the word from a team of scientists from Los Alamos National Laboratory, the U.S. Geological Survey, University of Arizona and several other partner organizations. In a paper published in Nature Climate Change, “Temperature as a potent driver of regional forest drought stress and tree mortality,” the team concluded that in the warmer and drier Southwest of the near future, widespread tree mortality will cause forest and species distributions to change substantially.

Separately, in the world’s two largest drought experiments, both based in New Mexico, Nate McDowell seeks to determine specifically why and where trees are dying. In a related story, a high-tech computer model called HIGRAD/FIRETEC, the cornerstone of a collaborative effort between the U.S. Forest Service Rocky Mountain Research Station and Los Alamos, provides insights that are essential for front-line firefighters. The team is looking into levels of bark beetle-induced conditions that lead to drastic changes in fire behavior and how variable or erratic the behavior is likely to be.

Tiny travelers could assist in healing Fukushima’s nuclear scar

Los Alamos National Laboratory scientists devised a method to use cosmic rays to gather detailed information from inside the damaged cores of the Fukushima Daiichi nuclear reactors, which were heavily damaged in March 2011 by a tsunami that followed a great earthquake.

Cosmic-ray radiography (also called muon radiography) uses secondary particles generated when cosmic rays collide with upper regions of Earth’s atmosphere to create images of the objects that the particles, called muons, penetrate.

The process is analogous to an X-ray image, except muons are produced naturally and do not damage the materials they contact.

Researchers compared two methods for using cosmic-ray radiography to gather images of nuclear material within the core of a reactor similar to Fukushima Daiichi Reactor No. 1. The team found that Los Alamos’ scattering method for cosmic-ray radiography was far superior to the traditional transmission method for capturing high-resolution image data of potentially damaged nuclear material.